Ignition system and engine

Abstract

The present invention relates to the technical field of internal combustion engines, and provides an ignition system, comprising: an engine body; a piston installed in the engine body; a cylinder head installed in an opening position of the engine body, wherein the engine body, the piston and the cylinder head define a main combustion chamber; and a pre-combustion device, comprising: a shell, arranged in the cylinder head and extending into the main combustion chamber; a pre-combustion chamber, formed in the shell; and a jet hole, formed at the end of the shell located in the main combustion chamber, for connecting the pre-combustion chamber and the main combustion chamber; a first injector, arranged on the shell, for injecting a first fuel into the pre-combustion chamber; and a second injector, arranged on the shell, for injecting a second fuel into the pre-combustion chamber, wherein at least a portion of the first fuel is compression-ignited in the pre-combustion chamber to ignite the second fuel. The present disclosure also provides an engine comprising an ignition system and a control unit.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engines, and in particular to an ignition system and an engine. Background Art

[0002] To effectively improve the stability and rapid combustion capability of an internal combustion engine based on lean-burn technology, prior art techniques involve configuring an internal combustion engine with a connected main combustion chamber and a pre-combustion chamber, with the same fuel in both chambers. The combustion in the main combustion chamber is then improved by adjusting the fuel-to-air equivalence ratio of the single fuel in the pre-combustion chamber.

[0003] In practical applications, the aforementioned internal combustion engine structure has limited control over the overall fuel-to-air equivalence ratio in the pre-combustion chamber, which can easily lead to reduced combustion stability and even misfires. Furthermore, for some fuels with low combustion activity, the lean burn in the main combustion chamber under low-load conditions cannot be achieved.

[0004] To this end, increasing the amount of spark plugs and the amount of fuel injected into the pre-combustion chamber can improve ignition performance to a certain extent. However, this places stricter demands on spark plug performance and ignition timing control. Furthermore, the increased amount of fuel injected into the pre-combustion chamber may also lead to increased pollutant emissions. Summary of the Invention

[0005] In response to the existing technical problems, the present invention provides an ignition system and an engine, which are used to at least partially solve the above technical problems.

[0006] One aspect of the present disclosure provides an ignition system, comprising: an engine body; a piston installed in the engine body; a cylinder head installed at an opening position of the engine body, the engine body, the piston and the cylinder head defining a main combustion chamber; and a pre-combustion device, comprising: a shell arranged in the cylinder head and extending into the main combustion chamber; a pre-combustion chamber formed in the shell; and a jet hole formed at an end of the shell located in the main combustion chamber, for connecting the pre-combustion chamber and the main combustion chamber; a first injector arranged on the shell for injecting a first fuel into the pre-combustion chamber; and a second injector arranged on the shell for injecting a second fuel into the pre-combustion chamber, wherein at least a portion of the first fuel is compression-ignited in the pre-combustion chamber to ignite the second fuel.

[0007] According to an embodiment of the present disclosure, the pre-combustion device is installed in the middle of the cylinder head.

[0008] According to an embodiment of the present disclosure, there are a plurality of the jet holes, and the plurality of the jet holes are formed at intervals at the end of the shell located in the main combustion chamber.

[0009] According to an embodiment of the present disclosure, the first fuel injector is disposed in the middle portion of the housing.

[0010] According to an embodiment of the present disclosure, the second fuel injector is disposed at an edge of the housing and forms an angle with the first fuel injector, so that at least a portion of the first fuel and the second fuel intersect in the pre-combustion chamber.

[0011] According to an embodiment of the present disclosure, the first injector includes: a first injector main spray hole, which is arranged at the axial first end of the first injector located in the pre-combustion chamber, and is used to spray the first fuel along the axial direction of the cylinder head; and a first injector auxiliary spray hole, which is arranged at a lateral position of the axial first end of the first injector, and is used to spray the first fuel along a direction other than the axial direction of the cylinder head; wherein the exit position of the first injector auxiliary spray hole is higher than the exit position of the first injector main spray hole.

[0012] According to an embodiment of the present disclosure, the second injector includes a second injector main spray hole, which is arranged at the axial first end of the second injector located in the pre-combustion chamber, and is used to inject the second fuel along the axial direction inclined to the cylinder head and intersect with the first fuel injected by the first injector main spray hole.

[0013] According to an embodiment of the present disclosure, the second injector further includes a second injector auxiliary spray hole, which is arranged at a lateral position of the axial first end of the second injector located in the pre-combustion chamber, for injecting the second fuel along the axial direction of the cylinder head.

[0014] The present disclosure also provides an engine, including an ignition system; and a control unit electrically connected to a first fuel injector and a second fuel injector, and adapted to control a ratio of a first fuel to a second fuel in a pre-combustion chamber.

[0015] According to an embodiment of the present disclosure, the engine further includes a monitoring unit adapted to monitor the load of the engine.

[0016] According to the ignition system and engine of the above-described embodiments of the present disclosure, a pre-combustion chamber is formed within the pre-combustion device. A first fuel injector and a second fuel injector are installed within the pre-combustion chamber, respectively for injecting a first fuel and a second fuel. At least a portion of the first fuel is compression-ignited within the pre-combustion chamber, which then gradually ignites the second fuel in the pre-combustion chamber and the main combustion chamber. The ignition system eliminates the need for spark plugs and adjusts the ratio of the first fuel to the second fuel to adjust the activity of the mixed fuel within the pre-combustion chamber. This effectively adapts to combustion conditions under various load conditions and promotes stable combustion of the fuels. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1is a cross-sectional schematic diagram of an ignition system according to an exemplary embodiment of the present disclosure;

[0018] Figure 2 yes Figure 1 An enlarged partial view of the ignition system of the illustrated exemplary embodiment;

[0019] Figure 3 yes Figure 2 A partial enlarged view of section A of the ignition system of the illustrated exemplary embodiment;

[0020] Figure 4 yes Figure 2 A state diagram of the fuel injection state of the illustrated exemplary embodiment;

[0021] Figure 5 yes Figure 4 A schematic diagram of the fuel activity gradient distribution of the exemplary embodiment shown in the low load state; and

[0022] Figure 6 yes Figure 4 A schematic diagram of the fuel activity gradient distribution of the exemplary embodiment shown in FIG. 1 is provided at medium to high load conditions.

[0023] Reference numerals

[0024] 1. Cylinder head;

[0025] 2. Shell;

[0026] 3. End cover of pre-combustion device;

[0027] 4. First fuel injector;

[0028] 41. Secondary spray hole of the first fuel injector;

[0029] 42. Main spray hole of the first injector;

[0030] 5. Top cover of pre-combustion device;

[0031] 6. Second fuel injector;

[0032] 61. Main spray hole of the second fuel injector;

[0033] 62. Second fuel injector auxiliary spray hole;

[0034] 7. Main combustion chamber;

[0035] 8. Body;

[0036] 9. Piston;

[0037] 10. Injector end cover;

[0038] 11. a first end of the housing;

[0039] 12. Pre-combustion chamber;

[0040] 13. Jet hole;

[0041] 14. a first fuel; and

[0042] 15. Second fuel. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0044] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0045] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0046] When expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.). When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.).

[0047] Figure 1 is a cross-sectional schematic diagram of an ignition system according to an exemplary embodiment of the present disclosure; Figure 2 yes Figure 1 An enlarged partial view of the ignition system of the illustrated exemplary embodiment; Figure 3 yes Figure 2 A partial enlarged view of section A of the ignition system of the illustrated exemplary embodiment; Figure 4 yes Figure 2 A state diagram of the fuel injection state of the illustrated exemplary embodiment; Figure 5 yes Figure 4A schematic diagram of the fuel activity gradient distribution of the exemplary embodiment shown in the figure under low load conditions; Figure 6 yes Figure 4 A schematic diagram of the fuel activity gradient distribution of the exemplary embodiment shown in FIG. 1 is provided at medium to high load conditions.

[0048] The present disclosure provides an ignition system, such as Figure 1 and Figure 2 As shown, it includes a body 8, a piston 9 installed in the body 8, a cylinder head 1 installed at the opening position of the body 8, and a pre-combustion device; the body 8, the piston 9 and the cylinder head 1 define a main combustion chamber 7; the housing 2 of the pre-combustion device is arranged in the main combustion chamber 7, and a first injector 4 and a second injector 6 are installed in the housing 2, and a pre-combustion chamber 12 and a jet hole 13 are also formed in the housing 2; wherein, the first injector 4 is used to inject a first fuel 14, the second injector 6 is used to inject a second fuel 15, and the jet hole 13 connects the pre-combustion chamber 12 and the main combustion chamber 7, and at least a portion of the first fuel 14 is compression-ignited in the pre-combustion chamber 12 and is used to ignite the second fuel 15.

[0049] Specifically, the first fuel 14 is a highly active fuel, and the second fuel 15 has a lower activity than the first fuel 14. A highly active fuel is characterized by the first fuel 14 being more easily combusted than the second fuel 15. It is preferred that the first fuel 14 be compression-ignited within the environment of the pre-combustion chamber 12 defined by the ignition system. The second fuel 15 can be a fuel that is less easily compression-ignited, such as gasoline, natural gas, or methanol.

[0050] Furthermore, the mixed fuel ignited by the first fuel 14 in the pre-combustion chamber 12 can form a flame jet or an active heat jet through the jet hole 13 .

[0051] According to the embodiments of the present disclosure, Figure 1 As shown, the pre-combustion device is installed in the middle of the cylinder head 1.

[0052] Specifically, the pre-combustion device is installed in the middle of the cylinder head 1, characterized by the pre-combustion device housing 2 being installed in the middle of the cylinder head 1 via the pre-combustion device end cover 3, and the fuel in the pre-combustion chamber can be scattered radially outward along the jet holes 13 of the cylinder head 1. It should be understood that the embodiments of the present disclosure are not limited thereto.

[0053] For example, the installation position of the pre-combustion device is not limited thereto and can be designed according to the actual cylinder structure and installation position to facilitate a more uniform diffusion of the mist beam formed by the second fuel 15 to the main combustion chamber 7 .

[0054] According to the embodiments of the present disclosure, Figure 1 and Figure 2 As shown, there are multiple jet holes 13 , and the multiple jet holes 13 are evenly spaced along the circumferential direction of the shell 2 .

[0055] In detail, the first end 11 of the housing 2 disposed in the main combustion chamber is provided with a jet hole 13 .

[0056] Furthermore, the number of the jet holes 13 is 6 to 8. It should be understood that the embodiments of the present disclosure are not limited thereto.

[0057] For example, the number of the jet holes 13 is 5 or less or the number of the jet holes 13 is 8 or more.

[0058] For example, the positions of the jet holes 13 can also be designed according to actual needs to form an uneven or asymmetric arrangement.

[0059] According to the embodiments of the present disclosure, Figure 1 and Figure 2 As shown, the first fuel injector 4 is arranged in the middle of the housing 2 .

[0060] According to the embodiments of the present disclosure, Figure 1 and Figure 2 As shown, the second fuel injector 6 is arranged at the edge of the housing 2 and forms an angle with the first fuel injector 4 so that at least a portion of the first fuel 14 and the second fuel 15 meet in the pre-combustion chamber 13. This allows the compression-ignited first fuel 14 to ignite the second fuel 15.

[0061] In detail, the first fuel injector 4 is arranged at the radial middle position of the housing 2 and roughly coincides with the center of the cylinder head 1 .

[0062] In detail, the second fuel injector 6 is arranged offset relative to the first fuel injector 4 .

[0063] Furthermore, the first fuel injector 4 and the second fuel injector 6 are both arranged on the pre-combustion device top cover 5 of the housing 2 and fixed by the fuel injector end cover 10.

[0064] According to the embodiments of the present disclosure, Figures 2 to 4 As shown, the first injector 4 includes a first injector main spray hole 42 and a second injector auxiliary spray hole 62 arranged at a lateral position of the first injector 4; wherein the first injector main spray hole 42 is located at the first axial end in the pre-combustion chamber 13, and is used to inject the first fuel 14 along the axial direction of the cylinder head 1, and the first injector auxiliary spray hole 41 is used to inject the first fuel 14 along the direction other than the axial direction of the cylinder head 1, and the exit position of the first injector auxiliary spray hole 41 is higher than the exit position of the first injector main spray hole 42.

[0065] According to an embodiment of the present disclosure, the second injector 6 includes an axial first end of the second injector 6 located in the pre-combustion chamber 12, which is used to inject the second fuel 15 along the axial direction inclined to the cylinder head 1 and intersect with the first fuel 14 injected by the main injection hole 42 of the first injector 4.

[0066] According to an embodiment of the present disclosure, the second injector 6 further includes a second injector auxiliary injection hole 62 arranged at a lateral position of the axial first end of the second injector 6 located in the pre-combustion chamber 12, for injecting the second fuel 15 along the axial direction of the cylinder head 1.

[0067] Specifically, the first fuel injector has multiple auxiliary nozzles 41, forming an acute angle with the first fuel injector main nozzle 42. The first fuel 14 and the second fuel 15 ejected from the first fuel injector main nozzle 42 merge to form a mixed fuel. The first fuel 14 ejected from the auxiliary nozzles 41 is positioned higher than the mixed fuel, thereby forming a localized high-concentration region of the first fuel 14 at a higher position within the pre-combustion chamber 12, which is more conducive to compression ignition.

[0068] Specifically, the second fuel injector secondary injection holes 62 are multiple in number and form an acute angle with the second fuel injector primary injection hole 61. The secondary injection holes 62 do not actively intersect with the first fuel 14, but instead extend downwardly along the axial direction of the cylinder head 1, thereby forming a localized high-concentration region of the second fuel 15 at a lower position in the pre-combustion chamber 12. It should be understood that the embodiments of the present disclosure are not limited to this.

[0069] For example, the number of the spray hole of the first fuel injector 4 and the second fuel injector 6 may be one.

[0070] Furthermore, the positioning of the injection holes of the first and second injectors 4 and 6 sequentially forms a "first fuel 14 high concentration region," a "mixed fuel region," and a "second fuel 15 high concentration region" within the pre-combustion chamber 12 from top to bottom. Within these three regions, the concentration of the first fuel 14 decreases from top to bottom, while the concentration of the second fuel 15 decreases from bottom to top, forming, from top to bottom, a high-activity region, a medium-activity region, and a low-activity region. During the compression stroke, under the action of a pressure differential, the cold jet from the pre-combustion chamber 12, consisting mostly of fuel from the medium- and low-activity regions, diffuses into the main combustion chamber 7, forming a highly active hot atmosphere at the center of the main combustion. The hot jet from the pre-combustion chamber 12, consisting mostly of fuel from the high- and medium-activity regions, ignites the surrounding areas of each jet, forming a distributed ignition pattern that ignites the low-activity or lean-burn fuel within the main combustion chamber 7.

[0071] The present disclosure also provides an engine, such as Figure 5 and Figure 6 As shown, it includes an ignition system and a control unit, wherein the control unit is electrically connected to the first injector 4 and the second injector 6, and is suitable for controlling the ratio of the first fuel 14 and the second fuel 15 in the pre-combustion chamber 12 to adjust the activity of the mixed fuel.

[0072] In detail, the control unit can adjust the activity of the mixed fuel by controlling the flow rate of the first injector 4 and the flow rate of the second injector 6.

[0073] Furthermore, the greater the ratio of the first fuel 14 to the second fuel 15 , the higher the activity of the mixed fuel.

[0074] According to an embodiment of the present disclosure, the engine further includes a monitoring unit adapted to monitor the load of the engine.

[0075] Specifically, the activity of the mixed fuel is adjusted according to the engine load.

[0076] like Figure 5 As shown, under the low-load state, the lower the load, the higher the concentration of the first fuel 14 , and the larger the volume occupied by the high-activity region I and the medium-activity region II in the pre-combustion chamber 12 .

[0077] like Figure 6 As shown, under medium and high load conditions, the higher the load, the higher the concentration of the second fuel 15 , and the larger the volume occupied by the medium activity region II and the low activity region III in the pre-combustion chamber 12 .

[0078] Furthermore, the piston 9 first descends from the top dead center, and fresh air or mixed gas enters the pre-combustion chamber 13; when the piston 9 passes the bottom dead center, the piston 9 ascends to compress the air or mixer in the cylinder, and the temperature and pressure in the pre-combustion chamber 12 increase accordingly; during the compression stroke, the first injector 4 and the second injector 6 begin to spray the corresponding fuel, and the first fuel 14 in the high-activity area of ​​the pre-combustion chamber 12 is compression-ignited, and then gradually ignites the mixed fuel in the low-activity area of ​​the pre-combustion chamber 12; after the fuel is burned, the pressure generated in the pre-combustion chamber 12 is higher than that in the main combustion chamber 7. Under the action of the pressure difference, the cold jet of the pre-combustion chamber 12 first enters the main combustion chamber 7, forming a hot atmosphere with higher activity at the center of the main combustion, and the hot jet of the pre-combustion chamber 12 follows the cold jet to ignite the surrounding area of ​​each jet to form a distributed ignition, which is used to ignite the fuel in the low-activity or lean-burn condition in the main combustion chamber 7.

[0079] The ignition system and engine provided in accordance with the present disclosure also have the following implementation effects: 1. The different activity stratifications formed by different fuels in the pre-combustion chamber 12 can effectively reduce the increase in combustion pressure in the pre-combustion chamber 12, which is beneficial to expanding the operating range; 2. By controlling the activity of the mixed fuel, the lean burn limit and the stable combustion capacity of the main combustion chamber 7 can be effectively improved, thereby meeting the combustion requirements under low-load conditions; 3. According to the real-time load changes of the engine, the proportion of fuel injected by the corresponding injector is adjusted, and the adjustment is more flexible, which is more conducive to more efficient and stable combustion of the engine under all operating conditions.

[0080] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. An ignition system, comprising: Body (8); A piston (9) installed in the body (8); A cylinder head (1) is mounted at an opening position of the engine body (8), wherein the engine body (8), the piston (9) and the cylinder head (1) define a main combustion chamber (7); as well as Pre-combustion device, comprising: A housing (2) disposed in the cylinder head (1) and extending into the main combustion chamber (7); A pre-combustion chamber (12) is formed in the shell (2); a jet hole (13) is formed at an end of the shell (2) located in the main combustion chamber (7) and is used to connect the pre-combustion chamber (12) and the main combustion chamber (7); a first fuel injector (4), arranged on the housing (2) and used for injecting a first fuel (14) into the pre-combustion chamber (12); and A second fuel injector (6) is arranged on the housing (2) and is used to inject a second fuel (15) into the pre-combustion chamber (12); the first fuel injector (4) and the second fuel injector (6) are arranged on a pre-combustion device top cover (5); wherein at least a portion of the first fuel (14) is compression-ignited in the pre-combustion chamber (12) to ignite the second fuel (15); The first fuel injector (4) is arranged in the middle of the housing (2), and the second fuel injector (6) is arranged at an edge of the housing (2) and forms an angle with the first fuel injector (4), so that at least a portion of the first fuel (14) and the second fuel (15) meet in the pre-combustion chamber (12). The first fuel injector (4) comprises: a first fuel injector main injection hole (42) disposed at an axial first end of the first fuel injector (4) located in the pre-combustion chamber (12) and used for injecting a first fuel (14) along an axial direction of the cylinder head (1); and A first fuel injector auxiliary injection hole (41) is arranged at a lateral position of an axial first end of the first fuel injector (4) and is used to inject a first fuel (14) in a direction other than the axial direction of the cylinder head (1); The ejection position of the auxiliary ejection hole (41) of the first fuel injector is higher than the ejection position of the main ejection hole (42) of the first fuel injector.

2. The ignition system according to claim 1, wherein: The pre-combustion device is installed in the middle of the cylinder head (1).

3. The ignition system according to claim 1, wherein: The number of the jet holes (13) is plural, and the plurality of jet holes (13) are formed at intervals at the end of the shell (2) located in the main combustion chamber (7).

4. The ignition system according to claim 1, wherein: The second fuel injector (6) comprises a second fuel injector main injection hole (61) arranged at an axial first end of the second fuel injector (6) located in the pre-combustion chamber (12) and used for injecting a second fuel (15) along an axial direction inclined to the cylinder head (1) and intersecting with the first fuel (14) injected by the first fuel injector main injection hole (42).

5. The ignition system according to claim 4, wherein: The second fuel injector (6) further comprises a second fuel injector auxiliary spray hole (62) arranged at a lateral position of the axial first end of the second fuel injector (6) located in the pre-combustion chamber (12) and used for injecting a second fuel (15) along the axial direction of the cylinder head (1).

6. An engine, comprising: An ignition system as claimed in any one of claims 1 to 5; as well as The control unit is electrically connected to the first fuel injector (4) and the second fuel injector (6), and is suitable for controlling the ratio of the first fuel (14) and the second fuel (15) in the pre-combustion chamber (12).

7. The engine according to claim 6, further comprising: A monitoring unit is adapted to monitor the load of the engine.

Images